Thanks guys. This brings up another question then: should I use the uniformer on ANY brass to open up the flash holes? I have never put this thing to a case that it didn't open the hole up a bit.

If the answer is no, why was this tool made other than to remove the burr inside the case? Rem and WW definitely have burrs, no doubt about that. Is there a flash-hole philosophy or methodology that I am unaware of that requires the flash-holes to be opened?

Thanks for the help with this question.

Maybe I can shed some light on this subject.

First= On Quality brass it is not nessary and if you open the hole up larger It will hurt accuracy
and SDs. Most bench rest cartriges use the small rifle primers with small flash holes to get a
hi velocity jet effect that burns the powder more consistently.

And to answer your question on why they even make a tool for this purpose, Flash holes are
made in the brass several ways,The quality brass is normally drilled and the less quality brass
is punched. The punched flash holes will some times have a finger nail of brass on the inside
that should be removed and if you use the uniformer you should use the smallest size that will
fit the largest of the holes(They will vary so only remove what is nessary to make them the
same). "Uniform".

Boomtube, that's my thought as well, but heck I not sure we really know whether Lapua drills, punches or mandrels the hole so I sent an email to Lapua asking but I'm not to hopeful they will respond as their site says they don't respond to questions but, maybe I'll get lucky. If I do hear back I'll share their response.